DTC B124C: Automatic High Beam Camera [08/2013 - ]: Procedure

WARNING: This page is about a different car, the 2014 Lexus ES 300h. However, it is still accessible from the selected car via links, so may be relevant.

CHECK FOR DTC (AUTOMATIC HIGH BEAM SYSTEM)

Clear the DTCs. Refer to DTC CHECK / CLEAR [08/2013 - ] .

Check for DTCs. Refer to DTC CHECK / CLEAR [08/2013 - ] .

Result

Result	Proceed to
DTC B124C is not output	A
DTC B124C is output (w/ Dynamic Radar Cruise Control System)	B
DTC B124C is output (w/o Dynamic Radar Cruise Control System)	C

B → See step 2

C → See step 5

A → See step 7

CHECK FOR DTC (LANE DEPARTURE ALERT SYSTEM)
1. Check for DTCs. Refer to DTC CHECK / CLEAR [08/2013 - ] .
  OK
  
  Lane departure alert system DTCs are not output.
NG → See step 9

OK: Go to next step
REPLACE LANE DEPARTURE WARNING CAMERA
1. Replace the lane departure warning camera with a new or known good one. Refer to REMOVAL [08/2013 - ] .
2. Check for DTCs. Refer to DTC CHECK / CLEAR [08/2013 - ] .
  OK
  
  DTC B124C is not output.
NG → See step 4

OK → END (LANE DEPARTURE WARNING CAMERA WAS DEFECTIVE)
REPLACE DRIVING SUPPORT ECU ASSEMBLY
1. Replace the driving support ECU assembly with a new or known good one. Refer to REMOVAL [08/2013 - ] .
2. Check for DTCs. Refer to DTC CHECK / CLEAR [08/2013 - ] .
  OK
  
  DTC B124C is not output.
NG → See step 8

OK → END (DRIVING SUPPORT ECU ASSEMBLY WAS DEFECTIVE)
CHECK FOR DTC (LANE DEPARTURE ALERT SYSTEM)
1. Check for DTCs. Refer to DTC CHECK / CLEAR [08/2013 - ] .
  OK
  
  Lane departure alert system DTCs are not output.
NG → See step 10

OK: Go to next step
REPLACE LANE DEPARTURE WARNING CAMERA
1. Replace the lane departure warning camera with a new or known good one. Refer to REMOVAL [08/2013 - ] .
2. Check for DTCs. Refer to DTC CHECK / CLEAR [08/2013 - ] .
  OK
  
  DTC B124C is not output.
NG → See step 8

OK → END (LANE DEPARTURE WARNING CAMERA WAS DEFECTIVE)
USE SIMULATION METHOD TO CHECK. Refer to HOW TO PROCEED WITH TROUBLESHOOTING [08/2013 - ]
REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to REMOVAL [08/2013 - ]
GO TO LANE DEPARTURE ALERT SYSTEM. Refer to DIAGNOSTIC TROUBLE CODE CHART [08/2013 - ]
GO TO LANE DEPARTURE ALERT SYSTEM. Refer to DIAGNOSTIC TROUBLE CODE CHART [08/2013 - ]